One hundred cases of primary spontaneous pneumomediastinum: leukocytosis is common, pleural effusions and age over 40 are rare

PSPM patients frequently present in their twenties with chest pain, subcutaneous emphysema, tachycardia, and leukocytosis. Approximately 25% have a history of retching or emesis and it is this population that must be discriminated from those with Boerhaave syndrome. An esophagram is rarely indicated and observation alone is appropriate in patients under age 40 with a known precipitating event or risk factors for PSPM (e.g., asthma, smoking) if they have no history of retching or emesis. Fever, pleural effusion, and age over 40 are rare in PSPM and should raise concern for esophageal perforation in a patient with a history of retching, emesis, or both.